A number of ceiling fans are known. A standard ceiling fan comprises a set of blades mounted about a first axis and a drive also mounted about the first axis for rotating the set of blades. Another type of ceiling fan generates a column of air downwardly into a room. For example, GB 2,049,161 describes a ceiling fan which has a domed support which is suspended from a ceiling, and a motor-driven impeller which is coupled to the inner surface of the support. An air stream emitted from the impeller is conveyed through a generally cylindrical body containing an array of air passages to generate a linear air stream which is emitted from the ceiling fan.